JP2750790B2 - Sheet adhesive and joining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for joining structural ceramic members and a method of using the same. Therefore,
Utilization is in the new ceramics industry.

[0002]

2. Description of the Related Art Conventionally, a brazing filler metal or an adhesive made of ceramic slurry has been used for joining oxide ceramic members. In these methods, the ceramic members are joined by filling or painting a portion to be joined and then firing.

[0003]

An object of the present invention is to provide a sheet-like adhesive material for joining an oxide-based ceramic member, to make the joining portion beautiful and to simplify the joining process.

[0004]

The adhesive of the present invention is provided in the form of a sheet sandwiched between release sheets.
This will be described below with reference to the drawings. FIG. 1 is a perspective view of an external appearance of a bonding material according to an embodiment of the present invention, which is partially cut out. In the figure, reference numeral 1 denotes an adhesive thin film;
Reference numerals a and 2b denote release sheets. As shown in the figure, a thin adhesive is sandwiched between two release sheets.

The adhesive thin film contains, as main components, ceramic powder to be fixed after firing, a synthetic resin emulsion as a temporary adhesive resin component, a surfactant for wetting and dispersing the ceramic powder, and water. . As the ceramic powder, a simple mixture of aluminum oxide, silicon oxide, or zirconium oxide, or a mineral containing them in an arbitrary ratio is mainly used. These proportions are 35 to 70% by weight of aluminum oxide and 30 to 50% of silicon oxide.
% By weight, zirconium oxide is 0 to 10% by weight, and titanium oxide, sodium oxide,
Oxide ceramics such as boron oxide and calcium oxide, or various vitrified compositions such as borax, feldspar, silicic acid, nitrite, soda ash, fluorspar, cryolite , limestone, slaked lime, bone ash, calcium carbonate, etc. 10% by weight is mixed. The particle size of these ceramic powders is preferably in the range of 0.1 to 50 μm. When the particle size is small, the surface activity increases, so that the sintering density increases and the shrinkage increases. Conversely, if it becomes larger, the surface activity becomes weaker, and the adhesive strength after firing does not increase. A particularly suitable range is a particle size of 0.1.
4 to 10 μm.

The synthetic resin emulsion is not particularly limited as long as it is aqueous, and various conventionally known synthetic resin emulsions can be used. Usually, polyacrylates and polyvinyl acetates are used. Thermoplastic resin emulsions such as polyvinylidene chloride-polyvinyl chloride, polyvinyl propionate, polyethylene-polyvinyl acetate, and polypropylene; reaction thermosetting resin emulsions such as urethane resin and epoxy resin; asphalt;
Bituminous emulsions such as rubber asphalt; synthetic rubber emulsions such as chloroprene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, methyl methacrylate-butadiene rubber, butadiene rubber, and the like, and mixtures thereof.

Among these synthetic resin emulsions, it is better to have tackiness in consideration of actually adhering the ceramic member temporarily, and a thermoplastic resin emulsion and a synthetic rubber emulsion are preferable. The adhesive thin film obtained by kneading with the ceramic powder or the like preferably has a value of 1.5 to 3 kgf / cm ² in the strength of the adhesive force. The present inventors measured the adhesive strength as 7 × 7 × 0.5.
cm of asbestos slate board, glue the peeled-off release sheet on one side with another epoxy resin adhesive,
The release sheet was peeled off on the other surface of the adhesive, and a steel adhesive attachment for measurement of adhesive strength (having an adhesive area of 2.5 × 2.5 cm polished with a water-resistant abrasive paper of No. 280) was attached. After being left under pressure for 15 minutes with a weight of 5 kg in weight, the adhesive strength was measured at a pulling speed of 2 mm / min using a tensile tester. This adhesive force is 1.5k
When it is smaller than gf / cm ^2, when using an adhesive, one release sheet is peeled off and adhered to the ceramic member to be joined, and when the other release sheet is peeled off, it floats on the adhesive thin film adhered to the ceramic member. May occur. On the other hand, if the adhesive strength is too large than 3 kgf / cm ² , it becomes difficult to separate the adhesive once and want to repair the adhesive part, and the workability deteriorates.

Further, the surfactant contained in the adhesive thin film includes an anionic surfactant, a nonionic surfactant,
Cationic surfactants and amphoteric surfactants are exemplified.
In addition to the compounding water, the following materials can be compounded in the adhesive thin film as long as the gist of the present invention is not impaired. That is, a water-soluble polymer (for example, carboxymethylcellulose, methylcellulose, hydroxyethylmethylcellulose, polyvinyl alcohol, gum arabic, modified maleic resin, dextrin, etc.) for improving the viscosity of the slurry for forming the adhesive thin film is added. May be. Further, in order to improve the drying property of the adhesive thin film, various solvents may be added (for example, alcohols, ketones, esters, cellosolves, amines,
And hydrophilic solvents such as acid amides). In addition, preservatives, fungicides, and the like can be added as necessary.

The mixing ratio of the ceramic powder, which is the main component of the slurry for forming the ceramic thin film, is determined by the total volume concentration (tentatively, ceramic volume concentration; CVC).
Is preferably 20 to 35%. This is CVC
Is small, the flammable components are burned out when temporarily bonded and fired, and the ceramic components are sintered with voids. In addition, when the CVC is increased, the fluidity of the ceramic slurry for forming the thin film is lost, and the adhesiveness becomes insufficient. In order to knead the ceramic powder and the synthetic resin emulsion or the like to form a slurry, a well-dispersed and defoamed one using a known mixing and dispersing apparatus is used.

In order to protect the adhesive thin film and facilitate storage and carrying, the present invention sandwiches the release film with a release sheet. A release sheet generally used as release paper can be used. As a suitable material, a plastic film such as polyethylene, polypropylene, or polyethylene terephthalate, or a material obtained by applying a silicone resin to a moisture-proof processed polyethylene-processed paper, vinylidene chloride-processed paper, or the like is used. To create an adhesive thin film from the ceramic slurry on a release sheet,
By the doctor blade method, a knife coater or the like is used as a machine to obtain an adhesive thin film having a desired film thickness. The film thickness is 0.3 to 1 mm from the viewpoint of economy and workability.
The thickness is appropriate.

[0011]

EXAMPLES In the examples, first, an emulsion was first selected, and then the value of the workability was determined by changing the amounts of the ceramic powder and the emulsion in order to determine the adhesive strength. In Table 1 below, the blending amount, adhesive strength as tackiness, workability, and appearance after firing are shown.

[0012]

[Table 1]

In the following Examples, ceramic powders shown in Table 2 below were kneaded by a pot mill using the ingredients shown in Table 3 to form ceramic slurries, vacuum defoamed, and coated with a release agent. A 0.5-mm thick PET film was applied on a 1-mm-thick PET film, dried at room temperature, and then overlaid on the PET film so that air did not enter.

[0014]

[Table 2] The numerical value indicating the ratio indicates parts by weight, and the other components include
Using minerals containing _{TiO 2, Na 2 O, K} 2 O, B 2 O 3, CaO and the like.

[0015]

[Table 3] The ceramic powder had the composition shown in Table 2. An acrylic resin copolymer (solid content: 50%) was used for the synthetic resin emulsion, and DBP was used for the film forming aid. The amount of water after kneading was 5000 in a rotary simple viscometer.
It was adjusted to be １５15000 cps.

The evaluation of the adhesion performance was performed using an alumina member 7 ×
An adhesive was stuck at a position where the square surface of the 3 × 3 × 2 cm member was aligned with the center of the 7 × 2 cm square surface, fired at a predetermined firing temperature and time, and the adhesive strength was measured. The results are shown in Table 4 below.

[0017]

[Table 4]

In the above test, the adhesive was attached to the flat portion and fired. In another embodiment, however, the adhesive was applied to the rising portions of the four sides of the flat plate to join the flat member and the prismatic member. They were pasted together, assembled into a sagger or setter, and fired. In this case as well, a clean finish was obtained without sagging of the adhesive during firing and no gap in the bonded portion. The sagger joined by the method of the present invention was repeatedly subjected to the heating test at 1500 ° C. ten times, and no abnormality occurred.

[0019]

The adhesive of the present invention can be used by cutting and attaching to the joining portion of the ceramic member, so that the joining can be performed easily and with a uniform thickness. In addition, since it is provided in a state sandwiched by the release sheet, storage and carrying are simplified. Further, unlike the conventionally used brazing material, the brazing material does not come off from the bonding portion, and the brazing material does not adhere to other portions to be stained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the adhesive of the present invention with a part cut away. 1. Adhesive thin film 2. Release sheet

Claims (3)

(57) [Claims] An adhesive thin film and temporary protection sandwiching the thin film;
An adhesive consisting of a release sheet for packaging, in which the thin film is composed mainly of silicon oxide, aluminum oxide, and zirconium oxide as ceramic powder, a synthetic resin emulsion as a resin for temporary bonding, and wetting and dispersion of ceramic powder. Containing surfactant and water for the blending of ceramic powder
A sheet-like adhesive characterized in that the volume concentration is 20 to 35% . 2. An adhesive thin film and temporary protection for sandwiching the thin film,
An adhesive consisting of a release sheet for packaging, where the thin film is
Silicon oxide, aluminum oxide, oxidation as lamic powder
Zirconium is the main component, and the
For wetting and dispersing resin emulsions and ceramic powders
Containing a surfactant and water, and
Aluminum oxide 35-70% by weight, silicon oxide
30 to 50% by weight, zirconium oxide 0 to 10% by weight
%, And titanium oxide, sodium oxide
Oxides such as thorium, boron oxide and calcium oxide
Ceramics or borax, feldspar, silica, saltpeter,
Ash, fluorite, cryolite, limestone, slaked lime, bone ash, charcoal
1-10 weight of various vitrified compositions such as calcium acid
% Adhesive, sheet-like adhesive
Wood. 3. An adhesive according to claim 1 or claim 2.
Material to the bonded section of the oxide ceramic member
Cut and release one sheet of release sheet
After peeling off another release sheet, it becomes a pair
After laminating the ceramic members, firing and fixing
And a joining method.